The important practical question following the death today of Congressman John Murtha is what happens to the House seat he held on behalf of the people of Pennsylvania's 12th District. The good news, so far as I can tell from early reports, is that Ed Rendell won't get to appoint an interim replacement, but rather the voters will have to choose one in a special election. As the Washington Post's Chris Cillizza reports:

According to state law, the governor has ten days once the vacancy is officially declared to decide on the date for the special election, which can come no sooner than 60 days following that proclamation.

That likely means the special election will be held on May 18, which is the date already set for federal primaries around the state. (Special elections costs the state huge sums of money and it's likely that Gov. Ed Rendell will choose to go with an already established election day to save some cash.)

Democrats have won every [House] special election in this Congress, including one pick-up from the GOP in New York 23. Another is set in the Florida 19th on April 13, with yet another seat opening soon when Rep. Neil Abercrombie (D-HI) steps down to run for governor.

In other words, there will be a couple more opportunities for voters to affect the composition of a House already narrowly divided on President Obama's signature issue, and for now, at least, there are no longer the votes to pass anything unless and until Nancy Pelosi turns some "no" votes into "yes" votes without losing more of the original "yes" votes.

PA-12 has trended Republican in recent years - Cillizza notes that it was the only district carried by John Kerry in 2004 to flip to McCain in 2008 - although it's hard to tell how much of that is due to Murtha-specific issues and to the hangover from Obama's ham-handed comments during the Pennsylvania primaries. My best advice to the PA GOP is to study carefully the mess made in NY-23 (the behind-closed-doors selection of a thin-skinned and too-liberal member of the dysfunctional, corrupt and discredited state legislature) before a candidate is chosen for this special election.